We chose this hotel because it's pretty renown and the overall experience was very good.

The Hotel.
The hotel is made up of three buildings that were reformed about 10 years ago. The buildings are lovely as well as its neighborhoods. I read many reviewers talking about "complicated access to the room": to be fair, it must be told that the three building are each on a different corner of a small crossroad. I suppose that the "complicated" access people is talking about is simply the little network of underground corridors that connects each building with one another. I don't know if people preferred crossing a rainy Galician road with only the bathrobe on and the hotel flip-flops, but to me it's just "good logistics".
Anyway, the rooms were spacious, bright and clean, with a small terrace facing the park behind the hotel and the view was lovely. The furniture was pretty simple but new, and the room was equipped with a flat screen television, a mini-bar and the heating/air conditioning system. The bathroom was spacious and equipped with everything you need. The personnel even provided me some extras because I forgot my beauty case at home and I was not charged for it.

The Restaurant.
The restaurant is good quality but pretty expensive (around 30 Eur per meal per person) and features an "internationalized" version of the typical Galician cuisine. The restaurant personnel if very kind and the maître is very professional.
It's probably worth reserving a room with half board and having a meal in one of the other (and cheaper) restaurant of the village. They're worth having a try, anyway.

Bars and Other Services.
The hotel has got a nice bar with live piano music in the week end (on a great, ancient and limited series Steinway & Sons piano). The bar features a lovely terrace just in front of the hotel outdoor pool.
During the weekend, an Italian Restaurant is available with hand made pizzas and other typical italian dishes.
The hotel has got an entertaining zone for kids, although this is not the kind of place where I'd took any children to and, indeed, there were very few of them.

The Spa.
The hotel pools aren't just a conventional spa. This hotel is built on a spring of thermal water and you can take advantage of them not only accessing the spa (called "Palacio del agua", which is roughly "Water Palace") but with a series of treatment packages as well. It's cheaper to include in the boarding price since it's pretty much cheaper. A single access to the spa costs around 20 Eur each and if you're willing to try some thermal treatments (we did, and they're worth trying) it's cheaper to buy one of the packages that the hotel offers.
The spa is pretty big: the ground floor offers a nice and big pool with the typical water jets you can find in a spa and a couple of different kinds of saunas. In the second floor you can find other saunas, an external thermal pool and a relaxing zone. The view from the spa is beautiful: the roof is a crystal dome and one of the external wall is made of glass panels from which you can see the hotel park.
At some hours the spa can indeed be crowded but we never had any problems with it: it's big enough and you're never waiting too much time.

The Treatments.
We chose this hotel because of its thermal waters and we weren't mistaken. We chose the relaxing treatments package (about 400 Eur each: 3 nights stay with half board) and it was up to our expectations. The daily treatment lasted about one hour and a half and it was performed in individual bathtubs with real thermal water. It was the first time for my girlfriend and she was surprised about the water color and its "rusty" smell: but that's what raw thermal water is supposed to be.

The Village.
The surrounding areas are lovely: it's a typical small galician village, built around the hotel, in the middle of the green. If you like walking, there are plenty of paths to explore. And if you don't like walking that much, it takes only a couple of minutes to reach the nearby river and enjoy some relaxing views of the greenest landscapes you can find in Spain. Galicia, moreover, it's an amazing country to discover, too much for this commentary to be exhaustive: if you feel like it, places such as Santiago de Compostela are pretty near (about 100km).